Re: Comments on Byte range draft

Wait wait, I keep on saying "if-not-modified-since" and you keep on
replying "if-modified-since". 

Normally, GET with caching uses 'if-modified-since', i.e., give me the
data if it's newer than/different from what I already have.

However, GET of a byte range need the converse. It's "give me this
byte range of this object, UNLESS the object is newer than/different
from what I already have".

The sense is different. HTTP doesn't have a "if-not-modified-since",
and would need it if you want byte ranges to actually work with data
that might change.